The field of load handling hardware includes many applications in which it is necessary to mechanically couple equipment to a chain. Examples include coupling an anchor rode to an anchor chain, coupling two chains together, and shortening the effective length of a chain.
Conventional load handling hardware coupling element designs include swivel eye hooks, bow shackles, quick-release snap shackles, trigger release shackles, harness clips, spring clips, and eye hooks. Examples of each of these conventional devices may be found on the Denver Rope website at <http://denverrope.com/chain-hardware.htm>, accessed 7 Mar. 2012.
Many of these conventional designs, including eye hooks, spring clips, harness clips, trigger release shackles, snap shackles, and bow shackles, have moving parts that may be damaged by hard use or the marine environment. Some conventional designs, such as swivel eye hooks, snap shackles and bow shackles, have complex load paths through swiveling mechanisms or threaded components. Conventional designs that feature multiple parts, such as bow shackles, are susceptible to loss of removable parts, such as the threaded pin of the bow shackle. Such conventional designs may not be sufficiently secure, strong and/or rugged for stressing load applications and environments.
Conventional designs, particularly those with moving parts such as threaded fasteners, do not lend themselves to quick and simple coupling and/or uncoupling of a chain.
The cost to manufacture conventional designs is driven by factors such as the complexity of fabrication, machining operations such as thread cutting, and/or assembly of multiple parts.
As can be understood, there is a need for a simple, inexpensive, strong, and rugged apparatus for quickly and securely coupling to a chain.